Field
Embodiments of the present disclosure generally relate to a method and apparatus for processing a web-based substrate.
Description of the Related Art
In web-based substrate processing, a substrate moves over rollers and is processed at one or more processing locations. As opposed to static processing, a web-based substrate may be processed as the substrate continuously moves through the system. As such, the substrate position is constantly changing, which is particularly noticeable in web-based substrate processing. The web-based substrate travels over rollers. When on the rollers, the substrate position is generally fixed. However, between rollers, the substrate may be stretched or move perpendicular/lateral to the path upon which the substrate is traveling. Stated another way, the substrate may wander so that when the substrate encounters the roller, the substrate is not in the same position on the roller for the entire length of the web-based substrate.
In addition to wandering, the substrate can be distorted such that the substrate “bunches up” or compresses in laterally relative to the substrate movement direction. When the distorted substrate reaches the roller, the distortion is generally fixed such that the distortion doesn't change for the portion of the substrate in contact with the roller. Processing a distorted substrate can pose numerous problems as the distortion can change along the length of the substrate as the substrate is moving through the system. Thus, either the substrate needs to be undistorted or the processing conditions need to change to compensate for the distortion.
One method to solve the substrate distortion problem is to use Self Aligned Imprint Lithography (SAIL). SAIL simply transfers the alignment problems among multiple lithography steps to multiple etching steps and is currently commercially impractical. SAIL processing requires a significant financial investment and very stringent system layouts and design rules.
Therefore, there is a need in the art for a method to process web-based substrates in a manner other than SAIL.